Method of making a slurry

ABSTRACT

An organic substrate is manufactured from recycled waste paper, cotton fiber and cotton gin waste, and gypsum. The recycled waste products are combined to form a slurry mixture for processing by conventional paper making machinery into a substrate that may be used in sheet form or comminuted pieces.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 09/814,606 filed on Mar. 22, 2001 now U.S. Pat. No. 6,399,185B1, which is a continuation-in-part application of U.S. patentapplication Ser. No. 09/182,488 filed on Oct. 30, 1998, now abandoned inthe name of Timothy D. Cathey and entitled “Method of ManufacturingAbsorbent Material for Conversion to Fertilizer”, a continuation-in-partapplication of U.S. patent application Ser. No. 09/498,987 filed on Feb.7, 2000, now U.S. Pat. No. 6,386,144 B1, in the name of Timothy D.Cathey and entitled “Method of Manufacturing Absorbent Material forConversion to Fertilizer”, and claims the benefit under 35 USC 121 ofUnited States Provisional Application No. 60/191,156 filed on Mar. 22,2000 in the name of Timothy D. Cathey and entitled “Method ofManufacturing Absorbent Material for Conversion to Fertilizer”.

FIELD OF INVENTION

The present invention relates to a method of manufacturing absorbentmaterials, and, more particularly, to a method of converting suchmaterials to a substrate for use as an organic mulch and seedgermination carrier.

BACKGROUND OF THE INVENTION

Methods for the manufacture of animal bedding products from waste paperpulp and other fibrous materials are well known to those skilled in theart. For example, U.S. Pat. No. 2,708,418 discloses an animal beddingproduct for use in the poultry industry that is manufactured from wastepaper pulp and other chemical additives. Animal bedding material formedfrom such a process has high absorptivity and drying characteristicsmaking it desirable for use as a bedding material in the poultryindustry.

U.S. Pat. No. 3,828,731 to White discloses a litter or bedding materialfor animals and a method of making the same. The litter is biodegradablein water and soil environments and is flushable through normal householdsanitary disposal systems. The litter consists primarily of high purityalphacellulose paper stock fibers in the form of pieces cut from a sheetof such material and into which has been incorporated microbialinhibitors.

U.S. Pat. No. 2,708,418 to Sugarman, et al. discloses an animal beddingmaterial manufactured from paper pulp adapted to absorb liquidsresulting from animal excrement. In this invention a pulp slurry isformed into pulp-board sheets, which are then cut and dried to thedesired size into which bacterial growth inhibitors are added.

U.S. Pat. No. 2,014,900 to Lapp discloses a process of manufacturinglitter suitable for poultry and livestock through the processing ofcottonseed hulls, a waste product of the cotton industry. The cottonseed hulls are treated with various chemical solutions containingquinine sulfate, pine oil, turpentine, and formaldehyde to produce thelitter.

U.S. Pat. No. 1,967,333 to Smith discloses an improved bedding materialfor poultry and animals using so-called bagasse i.e. the crushed andextracted waste from sugar-cane production, as the raw fibrous material.

U.S. Pat. No. 5,100,600 to Keller, et al. discloses a method of makingan absorbent paper-containing granulate which includes mechanicallycomminuting paper into irregular fragments, crumpling and interlacingthe fragments so as to create internal spaces therein, rough pressingthe interlaced and crumpled fragments into pre-pressed tubularformations, and converting the formations into granules or pellets. Thegranulate material can be used as litter or as an oil binding material.

U.S. Pat. No. 5,728,192 to Andrew, Jr., discloses a method of processingfibrous waste materials, such as textile waste, in which the wastematerials which are not particulate are formed into particles, and theparticles are thoroughly mixed to form a waste mixture. The wastemixture has an increased temperature which allows the mixture to be usedas a heat source as well as a plant growth medium.

U.S. Pat. No. 4,203,388 to Cortigene, et al. discloses an animal litterprepared by de-watering the rejects of a secondary paper fiber plant,incorporating a deodorant therein, for example, sodium bicarbonate,pelletizing, and drying.

U.S. Pat. No. 3,980,050 to Neubauer discloses a poultry litter which isabsorbent but capable of giving up absorbed liquids to the atmosphereunder conditions of usual use in poultry houses, such that the littertends to be maintained dry to the touch and uncompacted. The litter isitself a body of moisture-containing crumbs formed of low density barkand cellulosic fibrous material adhered to and carried by the bark.

U.S. Pat. No. 4,821,677 to Harrison discloses a method of making animallitter having improved absorbent and deodorizing qualities which utilizeground peanut hulls, peanut shells, and finally ground natural mineralin a dry mixture. The mineral constituent provides ionic bonding for thenitrogen ions in liquid animal waste to reduce the odor of animal litterexposed thereto.

U.S. Pat. No. 3,916,831 Fisher is considered of general interest in thatit discloses a system for animal excrement control which comprises theuse of popcorn as a means of absorbing and/or absorbing excrement.

Finally, U.S. Pat. No. 4,471,717 to Lander is considered of generalinterest in that it discloses a hydrophobic substantially non-absorbent,substantially non-water wettable granular material suitable for use as abedding for animals or for use as litter material in a waste receptaclefor animals.

Notwithstanding the foregoing approaches, in the poultry field inparticular the use of pine shavings has been the bedding of choice. Suchshavings had heretofore been widely available and relativelyinexpensive. Additionally, the shavings were highly absorbent of wastewith good evaporation characteristics permitting usage for extendedperiods without replacement. Lately, however, newly emerging woodproducts have reduced the availability and increased the cost of suchshavings. Shavings mixed wit (less effective) sawdust is used any manyareas. Moreover, the geographic distribution of poultry operations hasspread to areas where the shavings are not readily available. Afterexhaustion of efficacy, the spent shavings have no further applicationand must be disposed in accordance with environmental regulations, anadded cost for the poultry grower.

Accordingly, a need exists for improved bedding materials from readilyavailable, inexpensive sources providing efficacy and longevity in use,and minimizing or avoiding expensive disposal costs.

SUMMARY OF THE INVENTION

After much study and research into the prior art, the present inventionhas been developed to provide an absorbent bedding material manufacturedfrom a combination of recycled waste paper, waste cotton material, andgypsum using a water laid process and paper manufacturing equipment. Theresulting fibrous, highly absorptive material provides a usefullivestock bedding material having fire resistant characteristics due tothe gypsum content. The material can also be utilized in themanufacturer of absorbent cloth wipes and cage liners for researchanimals and pets.

After the absorbent material has been utilized, for example, as poultrybedding wherein it becomes saturated with nutrient-laden excrement, itis retrieved and undergoes further processing to become an slow releaseconstituent fertilizer and soil amendment.

The absorbent bedding material of the present invention also hasalternative uses such as absorbing and collecting liquid chemical spillsand the remediation of such chemical spills due to its biodegradablecomposition.

A further aspect of the invention is the utilization of the substrate,in sheet or comminuted form, as a barrier against weed growth inagricultural and horticultural uses. The barrier effectively preventsinvasive weed growth in crops grown in covered and/or fumigated plots,thereby substantially eliminating or reducing the need for chemicalfumigants, such a methyl bromide, and replacing plastic sheeting with abiodegradable tillable material. In another aspect of the invention thesubstrate in sheet form provides a growth medium for the hydroponicgermination of seeds, whereby the seeds adhered to the substrate withorganic adhesives effectively germinate and establish roots underconventional conditions. For lawn and other coverage grasses, thesubstrate with established root systems may be harvested withoutattendant soil for transplanting at site. On-site, the substratefunctions as a weed barrier and eventually biodegrades after theplanting is established.

In view of the above, it is an object of the present invention toproduce a highly absorptive material made from a combination of recycledpaper, cotton waste products, and gypsum for use as livestock bedding.

Another object of the present invention is to provide such an absorptivematerial by combining the constituent materials in a pulp slurry andforming the slurry into sheets using a water laid process and a varietyof paper manufacturing equipment.

Another object of the present invention is to provide a highlyabsorptive material which after being deployed as animal bedding andbecoming saturated with nutrient rich excrement, can be furtherprocessed into an organic fertilizer and soil amendment.

Another object of the present invention is to provide a highlyabsorptive animal bedding material having alternative uses such as forcollection of liquid chemical spills and for remediation of such spillsby biodegradation.

Another object of the present invention is to provide a highlyabsorptive animal bedding material having superior performancecharacteristics in comparison with comparable products on the market.

Yet another object is to provide a weed barrier material formed oforganic? materials that is tillable and biodegradable.

A further object is to provide a soil free carrier substrate forgerminating seed and establishing root systems thereon.

BRIEF DESCRIPTION OF DRAWINGS

The above and other objects and advantages of the present invention willbecome apparent upon reading the accompanying detailed description takenin conjunction with the following drawings in which:

FIG. 1 is a block diagram illustrating the overall method of the presentinvention; and

FIG. 2 is a block diagram showing the components of the paper makingequipment utilized in the present method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, there is shown therein a block diagramoutlining the steps in the method of the present invention illustratedin FIG. 1 and indicated generally at 10 for the manufacture from wastepaper, cotton and gypsum products and absorbent substrate collected atblock 11.

As an initial step in accordance with the present method, sufficientquantities of a wood pulp products such as old newsprint, mixed wastepaper, boxboard, corrugated board and similar materials are collected atblock 11 and undergo pre-processing at block 12 to eliminate extraneousmaterial, such as glue, hardware, excess coatings, clear windows andother foreign contaminants. A slurry mixture is formed at block 14 usingthe formulations described below, additives as required or desirable,are added at blocks 15 a and 15 b. The slurry is converted into sheetson papermaking machine at block 16, dried at block 17 a to a desiredmoisture content, and formed into rolls or sheets at block 17 b. Suchprocessed material may be inventoried at block 17 c for alternativeusage at block 17 d, such alternative uses discussed in greater detailbelow. For poultry bedding and other similar applications, the drymaterial in comminuted into appropriate shapes at block 18 a anddistributed as bedding at block 18 b. The material absorbs wasteaccumulations in use at block 19, and is subsequently retrieved anddried at block 21. From time to time during use the bedding may undergoscreening and conditioning at block 23. Subsequent to collection, thematerial is analyzed and additives incorporated at block 32 forconversion to fertilizer at block 35 a or ruminant feed product at block35 b.

Of course, such pre-processing operations may be carried out by themanufacturing activity or such paper waste materials may be purchased inready-to-use bulk particles or in pelletized form.

Similarly, the cotton mill waste, gin trash, gin motes, or post consumedcotton products must be cleaned, refined and sized to a sufficientextent to remove unwanted seed hulls and plant remnants to provide thecotton fiber.

Thereafter, the resultant cotton fiber is cut to a predetermined fiberlength in the range of 0.2 to 10 mm to provide optimum characteristicsin the finished product.

Gypsum can be obtained from recycled wallboard or in by-product formsuch as calcite gypsum from the manufacturer of other chemicals and mustbe screened and dressed to the proper particulate size. The hydratedgypsum adds flame-retardant qualities and the ability to assist inbonding nitrogen ions to reduce volatilization and loss when thefinished material is being used to absorb animal excrement.

Once the above constituent materials have been obtained in sufficientquantities and pre-processed, the formulation of a slurry mixture isconducted at block 14. As described below, highly absorbent and quickdrying substrates were formed using mixed waste paper in the range of10% to 90%, cotton fiber in the range of 10% to 90%, and hydrated gypsumin the range of 5% to 50% of the dry cotton weight. In the preferredembodiment, it has been determined that a formulation of 25% to 75%mixed waste paper, 25% to 75% processed cotton waste fiber, and 10% to45% solution of hydrated gypsum based on the moisture free cotton fiberweight provides optimum results. The combined slurry mixture is dilutedto approximately 1% to 10% total solids weight in the slurry or whateversolids weight is dictated by the paper manufacturing equipment.

Of course, the constituent quantities of the above formulation can varyover a wide range of percentages depending upon the density and dryingcharacteristics desired in the finished material. Similarly, the cottonfiber content may be varied based upon the fiber length, the degree towhich the fiber is refined or hydrapulped during pre-processing, and theabsorptivity for moisture required in the finished product. The specifictype of paper manufacturing equipment used to transform the slurrymixture into the finished paper sheets of the present method willdictate the slurry formulation.

Highly absorbent and quick drying sheet have been effectively processedinto sheet form on conventional paper making equipment in accordancewith the following examples.

EXAMPLE 1

Cotton mill waste was obtained in bale form and air-dried to yields 500pounds dry weight. Approximately 2000 gallons of cold water were addedto the mill was a processed in a Tornado Pulper at a consistency ofaround 3 to 3.5%. After pumping into a holding tank, the slurry wasuniform in appearance, with a dark gray-brown color. The slurry wastransferred to a blending tank and combined with 200 pounds of gypsumplaster hydrated in a conventional hydrapulper with hot water for about20 minutes. Thereafter, 30 bags of shredded newsprint in the amount ofabout 1500 dry pounds were added. The blend was transferred to ahydrapulper and diluted with warm water, 120° to 130° F., to provide a3% to 3.5% solids slurry. The slurry was processed to make a sheetthickness of 0.014 to 0.027 inch and dried to a moisture content of 6 to10%. The resultant sheet was chopped into small pieces. When immersed incold tap water, the pieces became saturated in 5 to 6 seconds indicationa high rate of absorbency.

Further formulations in accordance with the above were processed inaccordance with the following examples.

EXAMPLE 2

A slurry was formed comprising 85% mixed news print, 15% cotton millwaste refined a 0.3 mm clearance on a separator, 20% hydrated gypsum byweight of cotton mill waster and diluted with water to a 1% solidscontent was processed on wet process paper making equipment to form a0.010 to 0.022 inch thick sheet. The sheet was comminuted into piecesand exhibited excellent moisture absorbency and drying characteristics.

EXAMPLE 3

A slurry was formed comprising 75% mixed news print, 25% cotton millwaste refined a 0.65 mm clearance on a separator, 20% hydrated gypsum byweight of cotton mill waster and diluted with water to a 1% solidscontent was processed on wet process paper making equipment to form a0.025 to 0.040 inch thick sheet. The sheet was comminuted into piecesand exhibited moisture absorbency and drying characteristics comparableto Example 2.

EXAMPLE 4

A slurry was formed comprising 75% mixed news print, 25% cotton millwaste without refining, 40% hydrated gypsum by weight of cotton millwaster and diluted with water to a 1% solids content was processed onwet process paper making equipment to form a thick sheet. The sheet wascomminuted into pieces and exhibited excellent moisture absorbency anddrying characteristics.

At this dilution stage it is often desirable or advantageous to admix tothe slurry one or more chemical additives at block 15 which furtherenhance or promote the absorbency of the bedding material. In additionto or instead of absorbency enhancing additives, the present method caninvolve the admixture of natural disinfectants or a similar agent forthe purpose of preventing mold formation and inhibiting the growth ofdisease-producing microorganisms. In addition, various naturaldeodorants, flavoring agents, pH-adjusters, and dyestuffs may be addedto provide a specific characteristic.

The addition of various chemical additives to the slurry mixture isdependent upon the end use of the present material. If inhibition ofbacterial growth is desired, addition of a potassium compound such as pHadjusters is desirable at a rate to produce a finished material with apH of 8-9.

If the present bedding material is to be used with a pro-biotic andbacterial growth on the material is desired, addition of potassiumhydroxide is limited to produce a pH of 6.5-7.5 on average.

Other hydroxides of calcium, magnesium, and potassium can be added toproduce the desired pH.

In addition, other reactive compounds of the active metals can beadmixed to the slurry to enhance the nitrogen bonding characteristics ofthe absorbent material. However, care must be taken to insure that theadditives and resultant pH ranges do not contribute to skin irritationor other health problems of the livestock bedded on the presentmaterials.

Since such chemical additives are well known to those skilled in theart, further detailed discussion of the same is not deemed necessary.

As previously discussed, the slurry mixture undergoes processing inconventional paper making machinery into paperboard sheets at block 16.Referring to FIG. 2, there is shown therein a block diagram illustratingthe basic components and functions of a paper making machine, indicatedgenerally at 20. The machine 20 includes a receiving tank 22 wherein theslurry mixture is contained and agitated by a high-velocity, high volumepump 24 for the minimum time necessary to produce a homogeneous mixtureto eliminate “roping” of the fibrous material into elongated strands.

A pump 24 of the type known in the industry as a Moyno progressingcavity pump is suitable for this application. In this type of positivedisplacement pump, there is no rotating impeller that may become fouledby the circulating cotton fibers in the slurry, which cause theunacceptable roping or stringing effect about a rotating impeller.

Of course, various other types of pumps can be used to circulate theslurry mixture and the Moyno Progressing Cavity Pump is intended to bemerely illustrative and not restrictive in any sense.

The pump 24 delivers the slurry mixture to the so-called head box 26 ofthe paper machine wherein the slurry mixture is formed into sheetmaterial. It will be understood by those skilled in the art that if thethickness of the sheet material to be produced exceeds the capacity ofthe head box 26 a different paper machine of the type known in theindustry as a cylinder machine may be utilized in the present process.

Since such paper making machines are well known to those skilled in theart, further detailed discussion of the same is not deemed necessary.

Thereafter, the sheets undergo de-watering and are conveyed to a press28 for finishing to the desired thickness and subsequently to one ormore twin-roll presses (not shown) in which the moisture content of thesheet material is reduced further by mechanical pressing.

Next, the sheet material passes across heated drying rollers 30 whichcause the bulk of the moisture remaining in the sheet material toevaporate. At this stage various finishing additions may be applied tothe sheet material to adjust the pH and to provide other specificcharacteristics described hereinabove.

Thereafter, the dried sheet material obtained using the above process isready to be packed for storage or for shipment to distributors,retailers or individual users of the product, as at block 17 in FIG. 1.

The sheet material produced in accordance with the present methodexhibits a high specific absorbency two to eight times its weight inwater and quick drying, as well as exceptional fire-resistantcharacteristics due to the gypsum content. In addition, the finishedmaterial has an equally desirable ability to retain its shape in sheetform and not to break down into a substance of pulpy consistency, whichfacilitates shipping and handling of the material. The density of therolled material at finished thickness is approximatel 8-27 lbs. percubic foot. This density provides a sheet material in a form that packsefficiently on a truck and, thus, the load weight capacity of thevehicle is the only limiting factor in shipping.

If the absorbent sheet material is to be utilized as poultry bedding,the finished sheets are comminuted as at 18 into flat and random shapedpieces of a predetermined size having a maximum single dimension of 0.8inches (20 mm) and inclusive of 0.184 to 0.5 square inches single sideof surface area.

In the preferred embodiment generally 3-dimensional rectangular,triangular polygonal shapes or a mixture thereof having an angular fold,creates an absorbent wick with maximum loft depth using a minimum ofmaterial. In this form, the absorption rate and drying rate of thematerial make it an efficient poultry bedding even in reducedquantities.

The durability of the present material allows longer life of the beddingbefore it begins to decompose. The recommended application rate requiresabout 0.5 to 0.85 lbs. per square foot, which is about one-third therate of conventional pine shavings, providing an obvious cost advantage.

More particularly, the standard application rate for conventional pineshavings as poultry bedding varies from 4 to 8 inches of shavings on thefloor of the poultry house. The bedding material provided by the presentmethod weighs only one third that of pine shavings. Testing of thepresent bedding material has indicated significant improvements in feedto weight conversion in poultry at a bedding depth of two inches, whichis 0.58 pounds per square foot versus two inches of pine shavings whichweigh 1.82 pounds per foot or 3.14 times the weight of the presentbedding material.

The high absorbency of the present bedding material in combination withits biodegradable components and durability, permits saturation of thepresent material as at 19 with nutrient-rich compounds to provide anorganic fertilizer and soil amendment.

After raising multiple flocks over the durable absorbent beddingmaterial of the present invention, it can be cleaned of manure thatadheres to the surface thereof by a screening device as at 23 whichseparates the accumulated manure and redeposits the bedding for furtheruse.

After the optimum number of poultry flocks have passed over the presentbedding material and it starts to degrade, it may be retrieved and driedas at 21 and further processed to produce an organic constituentfertilizer as at 35.

This is accomplished by the use of a high capacity vacuum device (notshown) which can efficiently remove the saturated bedding material fordelivery to a microwave dryer or mineral dryer (not shown). The dryingprocess may be carried out at the site of the poultry farm or, in thealternative, the saturated bedding material may be transported to aremote processing site.

At the completion of the drying process, the saturated material issubject to chemical analysis as at 32 and other chemical amendments maybe added to balance the analysis of the organic fertilizer 35.Thereafter, the converted fertilizer is pelletized, bagged or bulkpackaged for shipping and distribution to contract yard services,retailers or individual users.

Further, the resultant nutrient rich material can also be utilized as aruminant feed or dietary supplement for animals such as cows afterchemical analysis and processing to eradicate harmful microorganisms.

From the above it can be seen that the method of the present inventionprovides an absorbent animal litter material, which is comprised ofrecycled waste products including mixed waste paper, cotton waste, andgypsum. The constituent materials are formed into sheets usingpaper-making equipment and converted into sized particles which serve asa bedding material in livestock operations such as poultry farming.

After becoming saturated with nutrient-rich compounds from livestockexcrement, the absorbent bedding material can be further processed intoan organic fertilizer and distributed to retailers or individual users.

Further, the present invention provides a versatile bedding material,which may be utilized in sheet form for caged research animals or petsand in small particle sizes for use as litter for a variety of livestockanimals.

In addition, the absorbent bedding material of the present inventionalso has alternative uses such as absorbing and collecting liquidchemical spills and the remediation of such chemical spills due to itsbiodegradable composition. It also functions as a weed barrier aroundplanting beds and gardens.

Finally, the saturated animal bedding material may also be used to feedruminant animals such as cows by careful attention to the ingredientsand chemical additives used during its manufacture.

The material as described as may also be utilized for preventing andretarding the growth of unwanted vegetation with respect to selectbiological species. For purposes of illustration, the material may beused in sheet or comminuted form as a barrier, cover, mulch or the likeagainst the growth of weeds and other undesired plant species inconjunction with horticultural applications including ornamental oreconomic vegetation, by way of example root vegetables grown in raisedbeds or around planting beds and gardens.

Therein the non-wood fiber can come from various agricultural residuesuch as flax, knaf, corn stalk, straw, grasses and weeds, and the like.The wood fiber and cellulosic material may include used news print,mixed office waste, box board, chip board, and fines from paper makingand other residue from the paper making process. The filler materialsmay comprise gypsum alone or in combination with calcium carbonate,lime, non-reactive mineral fillers, nutrient releasing materials, andthe residues from papermaking or paper recycling. Such applications mayalso benefit from the addition of wet strength additives and beappropriately increased in thickness for environmental resistance.Suitable wet strength additives include alum, rosin, and Kymene, aloneor in combination. The substrate thickness is appropriate for resistingthe local environmental conditions.

As barriers, the substrate has been demonstrated to inhibit weed growth,and at the end of the growing season, unlike conventional plasticbarriers, may be tilled into the soil. Weed control is the single mostimportant problem facing vegetable growers, particularly in the southAtlantic area of the United States. At present, a prevalent method ofcontrol uses a barrier sheet of plastic material and injection of methylbromide as a herbicidal fumigant therebelow. However, organic growersand small-scale farmers are hesitant to use plastic mulch inasmuch as itis a nonsustainable practice, non-biodegradable and difficult to removeat the end of the growing season. Moreover, due to environmentalconcerns, the use of methyl bromide is being phased out.

As a vegetation substrate, the present invention obviates and/orsubstantially reduces the need for methyl bromide fumigation. In onetype of agricultural application, the crop is planted by overlying thearea with a barrier of the present invention, piercing the barrier andimplanting the target seed or seedling.

EXAMPLE 5

A small-scale experiment was conducted in side-by-side trial with papermulch in sheet form and plastic mulch, 1.2 mil co-extruded white onblack polyethylene, and bare-ground control. Basic tested formulationsincluded 20% cotton, 80% old newsprint or used corrugated container,with 20% gypsum as filler. Secondary formulations may include rosin andalum for improved wet strength organic material, as well as Kymene, abrand of wet and dry strength additive used in paper processing. Theadditives may be in the range of about 0.5 to 4% of total fiber. Plotswere arranged in a randomized block design with four replications ofeach treatment. Each plot was 25 feet long with a raised bed. Beds wereestablished with a 30 inch planting area and a bed height of 10 inches.At time of bedding, the planting area was free of emerged weeds. Weedcounts were taken at 12 and 24 days after bedding. Excellent weedcontrol resulted from application of the paper mulch of the presentinvention. At day 24, nutsedge counts, per meter square were: 38 forbare-ground control plots; 36 for plastic sheet control plots; and 0 forthe paper mulch. Complete control was achieved for Carolina geranium,large crabgrass, nigthshade, thoroughwort, ragweed, commelina, andportulaca. Based on the foregoing results, the paper mulch was deemed todemonstrate excellent potential for weed control. The nutsedge controlwas considered particularly important as it is considered to be the mostimportant weed problem for growers in the planting area, and the mostlimiting factor for satisfactory organic production. The nutsedgecontrol achieved with the paper mulch was excellent and no nutsedgeemerged through the paper during the testing period. Nutsedge growingbeneath the paper mulch was chlorotic and stunted, posing no competitivethreat to any of the primary vegetable crops, including melons,tomatoes, strawberries, peppers, potatoes and lettuce. After removal ofthe paper mulch, residual control of nutsedge was maintained for over 30days.

The barrier may also be covered with adhered seed on the top surface,for horticultural applications including lawn grass and economicvegetation. Under suitable growing conditions, the seeds having beenfound to readily germinate with the root system growing through thebarrier. Germination is achieved over soil or and hydroponically. Inthese economic applications as well as ornamental deployment, thebarriers are gradually biodegradable. The resultant barrier reduces theneed for pre-emergence and post-emergence herbicides, retains soilmoisture, and reduces competition of unwanted plants for moisture,nutrient, and sunlight. Further, the material stabilizes soils, andreduces water erosion, soil transportation, and wind erosion. Thecarrier may also beneficially incorporate additives on the bottomsurface for promoting healthy growth including fungicides, growthstimulants and initial fertilizer amount.

EXAMPLE 6

Fescue and Bahia grass seeds were adhered to a carrier substrate inaccordance with the invention, using as an organic adhesive psilluimpaste. The carrier was kept moist throughout germinations and rootsystem formation in accordance with conventional practices. After fourweeks, evaluation determined the grasses grew well attached to thecarrier with the root systems established therebelow.

The foregoing substrate is also effective in limiting the soil transferof nitrogen compounds from amassed manure sources. In the livestockindustry, there has been increasing concern over an apparent transfermechanism that cause a large amount of the nitrogen in various chemicalforms to be driven from manures into the soil. Unpublished studiesappear to show that beneath a typical chicken house, there is enoughresidual nitrogen for supporting corn and cotton crops for extendedperiods, upwards of 100 years. As soil constituents, these nitrates andnitrites are though to pose problems in the water supply with resultingillness potential in humans. Additionally, increased nitrogen loadingposes additional pollution concerns in waterways. Initially, it wasthought the problem was exasperated by high water tables or moisturelevels in the litter of the broiler houses. Research to date has notconfirmed the above as a causal factor.

In accordance with the invention, this transport mechanism is overcomeby utilizing ionic chemicals to the substrate to reduce the ohmicresistance at prevailing litter moisture levels. Preferred additivesinclude magnesium oxide, powdered magnesium suspension or othersacrificial anodic material in combination with electrolytes such aspotassium hydroxide or sulfuric acid. In one beneficial system, thecombination is applied as a surface layer on the sheet prior tocomminuting. The material acts as a scavenger of nitrogen compounds.

The present invention may, of course, be carried out in other specificways than those herein set forth without departing from the spirit andessential characteristics of such invention. The present embodimentsare, therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

What is claimed is:
 1. A method of making a slurry comprising the stepsof: making a mixture by weight of about 10% to 90% paper-based pulp and10% to 90% cotton fiber having a fiber length of about 0.02 to about 10mm, and 2% to 85% gypsum by dry weight of cotton fiber; adding water tosaid mixture to form a slurry having a solids content by weight of about0.25% to 20%.
 2. The method as recited in claim 1 including the step ofprocessing said slurry to form a substrate.
 3. The method as recited inclaim 2 wherein said processing of said slurry is on paper makingmachinery to form said substrate.
 4. The method as recited in claim 2including the step of forming said substrate into discrete pieces. 5.The method as recited in claim 4 including the steps of comminuting saidpulp, cutting said cotton fiber to a length of about 0.02 to 10 mm, andforming said gypsum to a consistent size.
 6. The method as recited inclaim 1 wherein said mixture comprises by weight 25 to 75 percent paperpulp and 25 to 75 percent cotton fiber, and 10 to 45 percent gypsum.